Dose reduction in multislice CT by means of bismuth shields: results of in vivo measurements and computed evaluation

Catuzzo, P.; Aimonetto, Stefania; Fanelli, Guido; Marchisio, Paola; Meloni, Teodoro; Mistretta, L; Pasquino, Massimo; Richetta, E.; Tofani, Santi

doi:10.1007/s11547-009-0469-4

Cited by 42 publications

(40 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is an area of concern as the eye lens is one of the most radiosensitive organs in the human body. [17][18][19][20][21][22][23][24] According to the International Commission on Radiological Protection (ICRP), the radiation dose threshold for detectable lens opacities resulting in the formation of cataracts is 0.5 Gy.…”

Section: Dose Reductionmentioning

confidence: 99%

“…[17][18][19][20][21][22][23][24][25] Where as all studies report a reduction in dose to the eye, the dose savings vary from 20 to 50% depending on the scanner, technique and shield design. Mendes et al 23 conducted a study using an acrylic head phantom to evaluate the dose reduction achieved with and without the application of a bismuth shield covering the eyes.…”

Section: Dose Reductionmentioning

confidence: 99%

See 1 more Smart Citation

The Current Use and Effectiveness of Bismuth Shielding in Computed Tomography: A Systematic Review

Lawrence¹,

Seeram²

2017

Radiol Open J

View full text Add to dashboard Cite

CitationThe increased use of computed tomography (CT) has raised concerns regarding the radiation dose received by radiosensitive organs. It is important that practical and reliable dose reduction strategies are implemented to reduce patient radiation exposure. Aims: The purpose of this article is to evaluate the current clinical use and effectiveness of bismuth shielding as a dose reduction technique and assess its impact on image quality, in an attempt to develop a recommendation for dose reduction in CT. Methods: A systematic review of current literature was conducted using the PubMed and Scopus databases. A total of 50 relevant articles were thoroughly assessed and evaluated.Results: This review found that whilst bismuth shielding proves to provide significant dose reductions to radiosensitive organs, numerous concerns exist including wasted radiation, reduced image quality and unpredictable results when combined with AEC. Alternative methods such as tube current modulation and iterative reconstruction algorithms can provide equivalent dose savings at superior image quality, without the limitations of bismuth shields. Conclusion: Until these alternative methods become available in all departments, bismuth shielding remains a viable dose reduction strategy.

show abstract

Section: Dose Reductionmentioning

confidence: 99%

Section: Dose Reductionmentioning

confidence: 99%

The Current Use and Effectiveness of Bismuth Shielding in Computed Tomography: A Systematic Review

Lawrence¹,

Seeram²

2017

Radiol Open J

View full text Add to dashboard Cite

show abstract

“…10 A thyroid collar was found to reduce radiation doses significantly during CT scanning of the head. [11][12][13][14] However, until now there have been no studies published to evaluate the radioprotective effects of thyroid collars during CBCT scanning. The aim of this study was to evaluate the radiation dose of CBCT when applying thyroid collars.…”

Section: Introductionmentioning

confidence: 99%

Dose reduction of cone beam CT scanning for the entire oral and maxillofacial regions with thyroid collars

Li²,

Sanderink³

et al. 2012

Dentomaxillofacial Radiology

View full text Add to dashboard Cite

Objective: The aim of this study was to evaluate the influence of thyroid collars on radiation dose during cone beam CT (CBCT) scanning. Methods: Average tissue-absorbed dose for a NewTom 9000 CBCT scanner (Quantitative Radiology, Verona, Italy) was measured using thermoluminescent dosemeter chips in a phantom. The scans were carried out with and without thyroid collars. Effective organ dose and total effective dose were derived using International Commission on Radiological Protection 2007 recommendations. Results: The effective organ doses for the thyroid gland and oesophagus were 31.0 mSv and 2.4 mSv, respectively, during CBCT scanning without a collar around the neck. When the thyroid collars were used loosely around the neck, no effective organ dose reduction was observed. When one thyroid collar was used tightly on the front of the neck, the effective organ dose for the thyroid gland and oesophagus were reduced to 15.9 mSv (48.7% reduction) and 1.4 mSv (41.7% reduction), respectively. Similar organ dose reduction (46.5% and 41.7%) was achieved when CBCT scanning was performed with two collars tightly on the front and back of the neck. However, the differences to the total effective dose were not significant among the scans with and without collars around the neck (p 5 0.775). Conclusions: Thyroid collars can effectively reduce the radiation dose to the thyroid and oesophagus if used appropriately.

show abstract

“…In several studies, reduction in radiation doses to the thyroid and the eye with bismuth shielding was shown regarding CT operating at 120 kVp (11,23,24). Inkoom et al (25) investigated the effect of bismuth shielding on thyroid dose and image quality in CT with fixed exposure parameters using pediatric anthropomorphic phantoms representing the equivalent newborn and 10-year-old child and reported a 17% and 35% decrease in thyroid dose, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…Any air spaces or wrinkles in the shielding substance will result in significant beam hardening artifact. In addition to these findings, there are findings regarding decreased dosage without loss of image quality (11,23). In 2012, The American association of physicists in medicine (AAPM) (27) published its stance on the use of bismuth shields to achieve dose reduction and recommended that alternative methods should be considered and applied whenever possible.…”

Section: Discussionmentioning

confidence: 99%

Are Bismuth Shields Useful in Dentomaxillofacial Radiology Practice for the Protection of Eyes and Thyroid Glands from Ionizing Radiation?

et al. 2017

View full text Add to dashboard Cite

Background: The eye lens and thyroid gland are sensitive to radiation and have a risk of being exposed to primary beams and scattered radiation during dental radiographic examinations. Objectives: The present study was aimed to evaluate the effectiveness of bismuth shielding in decreasing eye lens and thyroid radiation dose in periapical radiography (PR), orthopantomography (OPTG), and cone beam computed tomography (CBCT) examinations. There is no information in relevant literature regarding the use of bismuth shielding in dental radiology. Materials and Methods: Dose measurements for PR, OPTG and CBCT were conducted by placing thermoluminescent dosimeter chips on the eye and thyroid location in a standard head phantom. Each one of the scan techniques was performed without any bismuth shielding, and they were then repeated with bismuth shielding in place. The percent dose reduction from bismuth shielding was calculated by dividing the dose measured with bismuth shielding by the dose measured without bismuth shielding. Results: The eye dose was observed to decrease in bismuth shielding group in PR, however it was not statistically significant. The thyroid dose was found to be significantly decreased in PR (P < 0.05). In OPTG and CBCT scans, both the dose to the eye and the thyroid gland was observed to increase by using bismuth shielding. Among these, only the increase in the eye dose in CBCT was not statistically significant (P > 0.05). Conclusions: This study demonstrated higher thyroid and eye lens dose with the use of bismuth shielding in OPTG and CBCT scanning. However, due to the significantly decreased thyroid dose in PR, it may be recommended as an alternative to leaded shielding in periapical radiographic examinations.

show abstract

Dose reduction in multislice CT by means of bismuth shields: results of in vivo measurements and computed evaluation

Cited by 42 publications

References 10 publications

The Current Use and Effectiveness of Bismuth Shielding in Computed Tomography: A Systematic Review

The Current Use and Effectiveness of Bismuth Shielding in Computed Tomography: A Systematic Review

Dose reduction of cone beam CT scanning for the entire oral and maxillofacial regions with thyroid collars

Are Bismuth Shields Useful in Dentomaxillofacial Radiology Practice for the Protection of Eyes and Thyroid Glands from Ionizing Radiation?

Contact Info

Product

Resources

About